The dynamic changes of zinc transporter 8 autoantibodies in Czech children from the onset of Type 1 diabetes mellitus

Aims The prevalence of autoantibodies to zinc transporter 8 (ZnT8) in Czech children at the onset of Type 1 diabetes mellitus and dynamic changes in ZnT8 autoantibody levels during disease progression were studied. The value of ZnT8 autoantibody measurements in diagnosis of Type 1 diabetes was assessed. Methods Serum samples from 227 children with newly diagnosed Type 1 diabetes and from 101 control children without diabetes were analysed in a retrospective cross‐sectional study. One hundred and seventy‐one samples from 116 of the patients with diabetes were analysed in a follow‐up study at (median) intervals of 1, 3, 5 and 10 years after onset of Type 1 diabetes. ZnT8 autoantibodies were measured using a bridging enzyme‐linked immunosorbent assay, while antibodies to glutamic acid decarboxylase, insulinoma antigen 2 and insulin were measured by radioimmunoassays. Results ZnT8 autoantibodies were detected in 163/227 (72%) of children at Type 1 diabetes onset and in 1/101 (1%) of the control subjects. Sixteen out of 227 (7%) patients with Type 1 diabetes were antibody negative based on three antibodies (glutamic acid decarboxylase, insulinoma antigen 2 and insulin). This false‐negative rate was reduced to 10/227 (4.4%) (P